/*
 * Copyright 2008 Bob Schellink
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package net.sf.click;

import net.sf.click.util.Partial;

/**
 * Provides an Ajax ActionListener.
 *
 * @author Bob Schellink
 */
public interface AjaxListener extends ActionListener {

    /**
     * This method is invoked for ajax requests and returns a
     * {@link net.sf.click.util.Partial} response.
     * <p/>
     * A Partial instance represents a partial response to a user request.
     *
     * @param source the source of the action event
     * @return the partial response to render, or null if no response should
     * be rendered
     */
    public Partial onAjaxAction(Control source);

}
